FLIGHT 4U9525 ISSUED EMERGENCY "7700" SQUAWK TO AIR TRAFFIC CONTROL BEFORE DESCENDING

16 GERMAN SCHOOLCHILDREN BELIEVED TO BE ON BOARD

MAJORITY OF A320 PASSENGERS WERE SPANISH OR GERMAN

WEATHER WAS CALM AT TIME OF CRASH AND THERE DIDN'T APPEAR TO HAVE BEEN TURBULENCE

CAPTAIN HAD FLIGHT EXPERIENCE OF MORE THAN 10 YEARS AND MORE THAN 6,000 FLIGHT HOURS

An Airbus A320 crashed en route to Dusseldorf from Barcelona, likely killing all 150 people on board, in what would be the worst air accident on French soil in three decades.

Germanwings Flight 9525 operated by the low-cost subsidiary of Deutsche Lufthansa AG went down in the French Alps following a rapid descent from cruising altitude, France’s civil aviation authority said. Wreckage has been sighted, and French President Francois Hollande said there are unlikely to be any survivors.

“This is a tragedy that has happened on French soil,” Hollande said in Paris. “We need to show all support in the face of this drama.”

Investigators are racing to establish the cause of the crash, which doesn’t follow any typical disaster pattern. The loss involves a reliable and widely flown aircraft traveling at cruising altitude -- typically the safest part of a journey -- on a busy route in broad daylight and good weather. European politicians suspended their agendas to coordinate the crisis response, with German Chancellor Angela Merkel planning to travel to the region tomorrow to witness the salvage mission.

It’s too early to speculate on possible causes without more information, said John Cox, the head of aviation safety consulting firm Safety Operating Systems LLC in Washington. Investigators will examine the debris field to see if the plane came apart in flight or flew into the ground. The size of the debris also can be telling, with smaller pieces meaning a higher-speed impact.

Hunting for evidence

“They’re going to be looking for the black boxes very strongly and will listen to the tapes of the radio transmissions and see if there was anything the crew might have said to air traffic control that has not been released,” Cox said. “You look at everything -- the weather, the crew, the maintenance history, the airplane history.”

The A320 single-aisle jet, an industry workhorse used on shorter distances, is Airbus’s most popular model, and the planes are typically operated with about 150 passengers. Germanwings said 144 passengers and six crew were on the crashed plane.

Rapid descent

French air traffic controllers in the region declared an emergency at 10:47 a.m. as they saw the plane descending rapidly, said Eric Heraud, a spokesman for French civil aviation authority DGAC. The plane plummeted from 38,000 feet (11,600 meters) to 5,000 feet while flying over the town of Barcelonnette in the Alpes de Haute-Provence region, he said.

Germanwings said contact was lost at 10:53 a.m., less than 10 minutes after the aircraft had reached cruising altitude. Air-traffic controllers didn’t give approval for the descent, Germanwings said at a press conference in Cologne.

Flight-tracking service FlightAware showed the plane cruising on a northeasterly heading at about 38,000 feet before it suddenly began a steep descent, shedding more than 25,000 feet of altitude in seven minutes.

“Although we did track the airplane in the descent to 11,400 feet, the final position reflects the end of our flight tracking coverage for this flight and does not indicate the accident site,” FlightAware Chief Executive Officer Daniel Baker said in an e-mailed statement. “Only the French government will definitively provide that information.”

France’s BEA accident investigator is opening an investigation immediately, said spokeswoman Martine Del Bono. The organization has oversight for all air crashes on French territory and would also participate in any probe involving a plane made by a French company.

Rugged terrain

The crash is the deadliest on French soil since 1981, when a DC-9 jetliner flown by Slovenia’s Adria Airways went down near Mont San-Pietro and killed 180 people, according to data compiled by Aviation Safety Network, a project of the Alexandria, Virginia-based Flight Safety Foundation.

France’s only accident this century even approaching the scope of the Germanwings disaster occurred in 2000, when an Air France Concorde struck runway debris on takeoff and was engulfed in flames, killing all 109 people on the supersonic jet and four on the ground.

German, French and Spanish authorities have set up crisis-response teams, and Hollande said he’s coordinating efforts with Merkel’s government. Merkel “is deeply shocked by the German aircraft’s crash,” Steffen Seibert, her chief spokesman, said in an e-mailed statement. Merkel has canceled other appointments and will keep up-to-date on developments in the hours ahead, he said.

Good weather

Germanwings operates Deutsche Lufthansa’s European routes outside of the German carrier’s main Frankfurt and Munich hubs. The move was designed for Lufthansa to better compete against budget carriers in Europe. Lufthansa, like its European peers, has come under pressure to lower costs as more people opt for no-frills airlines on shorter distances.

The actual crash site is at a higher altitude in the Le Vernet, near Prads-Haute-Bleone. Firemen and rescue teams are reaching the area, which is is about 58 miles northwest of Nice and 25 miles west of the Italian border, in a region of Provence popular with hikers and campers in the summer.

Radar images from Meteo-France showed no showers in the area at 10:30 a.m., minutes before the reported crash time. A weather station in Seyne, less than 10 kilometers north of the reported crash site, measured winds of 3 kilometers per hour at the time with gusts up to 9.7 kilometers per hour, a light breeze on the Beaufort scale.

Experienced pilot

Airbus said it’s focusing “all efforts” on assessing the situation, and that it’s been informed about an accident that involves one of the Toulouse, France-based products. The A320 aircraft is by far Airbus’s most widely flown model, and the aircraft has been popular with carriers around the world because it serves a key segment of the market and is equipped with advanced technologies such as fly-by-wire controls.

Germanwings said the aircraft involved in the accident was delivered to Lufthansa in 1991 and was flown by a pilot with 6,000 hours of Airbus flight experience. The plane had been serviced last summer and had logged 46,700 flights. The aircraft had flown to Barcelona this morning, the airline said.

Among the victims, 67 were probably of German nationality, Germanwings said. Lufthansa Chief Executive Officer Carsten Spohr said he’ll travel to the crash site with German representatives including Transport Minister Alexander Dobrindt.